<template>
  <div class="chart flex width-100 justify-around">
    <div ref="chart" :style="{ height: height, width: width }"/>
    <slot></slot>
  </div>
</template>
<script>

// 引入 echarts 核心模块，核心模块提供了 echarts 使用必须要的接口。
import * as echarts from 'echarts/core'
// 引入柱状图图表，图表后缀都为 Chart
import {
  BarChart,
  PieChart,
  LineChart
} from 'echarts/charts'
// 引入提示框，标题，直角坐标系组件，组件后缀都为 Component
import {
  TitleComponent,
  TooltipComponent,
  GridComponent,
  LegendComponent,
  DataZoomInsideComponent,
  DataZoomSliderComponent
} from 'echarts/components'
// 引入 Canvas 渲染器，注意引入 CanvasRenderer 或者 SVGRenderer 是必须的一步
import {
  CanvasRenderer
} from 'echarts/renderers'
import {shallowRef} from 'vue';
// 注册必须的组件
echarts.use(
    [TitleComponent, TooltipComponent, GridComponent, BarChart, CanvasRenderer, PieChart, LineChart, LegendComponent, DataZoomInsideComponent, DataZoomSliderComponent]
)

export default {
  name: 'ChartView',
  props: {
    width: {
      type: String,
      default: '100%'
    },
    height: {
      type: String,
      default: '350px'
    },
    autoResize: {
      type: Boolean,
      default: true
    },
    chartOption: {
      type: Object,
      required: true
    },
    type: {
      type: String,
      default: 'canvas'
    }
  },
  data() {
    return {
      chart: null
    }
  },
  watch: {
    chartOption: {
      deep: true,
      handler(newVal) {
        this.setOptions(newVal)
      }
    }
  },
  mounted() {
    this.initChart()
    if (this.autoResize) {
      window.addEventListener('resize', this.resizeHandler)
    }
  },
  unmounted() {
    if (!this.chart) {
      return
    }
    if (this.autoResize) {
      window.removeEventListener('resize', this.resizeHandler)
    }
    this.chart.dispose()
    this.chart = null
  },
  methods: {
    resizeHandler() {
      this.chart.resize()
    },
    initChart() {
      this.chart = shallowRef(echarts.init(this.$refs.chart, '', {
        renderer: this.type
      }))
      this.chart.setOption(this.chartOption)
      this.chart.on('click', this.handleClick)
    },
    handleClick(params) {
      this.$emit('click', params)
    },
    setOptions(option) {
      this.clearChart()
      this.resizeHandler()
      if (this.chart) {
        this.chart.setOption(option)
      }
    },
    refresh() {
      this.setOptions(this.chartOption)
    },
    clearChart() {
      this.chart && this.chart.clear()
    }
  }
}
</script>
<style scoped lang="scss">
.chart {
  position: relative;
}
</style>

